Figure 3A. Magnetic Resonance Spectroscopy Measurement of GABA/water and Glx/water concentrations in Medial Prefrontal Cortex in Major Depressive Disorder before (baseline frame), during (frame 1–4-) and after (frame 5–6) an intravenous ketamine infusion (40 minutes duration). Frame duration was 13:20 minutes. Asterisks denote statistically significant group increases in GABA and Glx concentrations relative to pre-ketamine baseline levels.
Abbreviations: GABA/W, mean of water-corrected γ-aminobutyric acid level; Glx/W, mean of water-corrected glutamate + glutamine level. Error bars denote standard deviation from the mean.
Figure 3B. Individual subjects’ Glx/W and GABA/W responses to ketamine as measured by the area under the curve. Abbreviations: AUC, area under the curve; GABA/W, water-corrected γ-aminobutyric acid level; Glx/W, sum of water-corrected glutamate + glutamine level.